I have sent a more detailed message to "postmaster@tpg.com.au", but have not had a response. Over recent weeks I have been unable to receive emails to my @TPG.com.au account from the domain @stjohnsa.com.au Until recently I received emails from this domain very regularly and am not aware of any changes to my settings that may have contributed to this issue. I am still receivng emails from numerous other sources and have been able to receive emails from @stjohnsa.com.au to an alternative account (a gmail rather than a @TPG.com.au account). Please help..... ... View more

I am receiving the message below when attempting to send an email to one specific address. No problems with other addresses. Have ensured POP accounting setings are as advised in other posts, including activating SMTP Authentication. Are there other setting I need to change?   _______ The original message was received at Wed, 13 Oct 2021 18:13:35 +1100 from 110-174-101-26.tpgi.com.au [110.174.101.26]   This message was generated by rpt-cro-mail01.tpgi.com.au      ----- The following addresses had permanent fatal errors ----- <xxx.xxxxxx@dvesolutions.com.au>     (reason: 550-Please turn on SMTP Authentication in your mail client. )      ----- Transcript of session follows ----- ... while talking to dvesolutions.com.au.: >>> DATA <<< 550-Please turn on SMTP Authentication in your mail client. <<< 550-rpt-cro-mail01.tpgi.com.au [60.241.0.56]:41764 is not permitted to relay <<< 550 through this server without authentication. 550 5.1.1 <xxx.xxxxx@dvesolutions.com.au>... User unknown <<< 503-All RCPT commands were rejected with this error: <<< 503-Please turn on SMTP Authentication in your mail client. <<< 503-rpt-cro-mail01.tpgi.com.au [60.241.0.56]:41764 is not permitted to relay <<< 503-through this server without authentication. <<< 503 Valid RCPT command must precede DATA ... View more